Love Delta, located on the outskirts of Geduld Sea, serves as a training base for Kouji Aiba and Aoi Housen, aspiring astronauts in AD 2225. During a conventional dive procedure, unidentified attackers with unknown motives create chaos, causing the space station to plunge into the Geduld, a plasma field that links planets together in a nervous system-like manner, and destroys any vehicle that ventures too far. All adults onboard perish, leaving the young astronauts to face the arduous journey home, as conflicts among them intensify. Meanwhile, those responsible for the attack gear up for another strike.